code: def _operator(self):
      return operator.sub
  
file_path: mars/mars/dataframe/arithmetic/subtract.py
imports: import operator
  from ...None import opcodes
  from ...utils import classproperty
  from .core import DataFrameBinopUfunc
  from .docstring import bin_arithmetic_doc
label_desc: Use image node_id 1 for calling the DataFrameSubtract obj's underlying member method code with example usage: obj._operator() and returns: operator